WCF动态添加ServiceKnownType

WCF中传输自定义类型时，必须在服务接口类（服务协定）上加上ServiceKnownType(typeof(yourClass)),

在实际应用中比较麻烦，可以用动态的办法来实现动态添加。

服务接口类，加上一行 [ServiceKnownType("GetKnownTypes", typeof(KnownHelper))]

再实现定义类KnownHelper及方法GetKnownTypes

    [ServiceContract]
    [ServiceKnownType("GetKnownTypes", typeof(KnownHelper))]
    public interface IService
    {
        [OperationContract]
        DataSet GetData(Hashtable hash);
    }
 static class KnownHelper
    {
        public static IEnumerable<Type> GetKnownTypes(ICustomAttributeProvider provider)
        {
            List<Type> knownTypes = new List<System.Type>();
            string[] types = null;
            if (System.Configuration.ConfigurationManager.AppSettings["KnownTypes"]!=null)
            {
                types = System.Configuration.ConfigurationManager.AppSettings["KnownTypes"].ToString().Split('|');
                foreach (string type in types)
                {
                    knownTypes.Add(Type.GetType(type));
                }
            }
            return knownTypes;
        }
    }

 这内我用的办法把需添加ServiceKnownType的类型名称写到配置文件的AppSettings内，当然也可以用其他办法，比如文件。